Novel functional blueberries: Fructo-oligosaccharides and probiotic lactobacilli incorporated into alginate edible coatings

Abstract

Minimally processed fruits are an alternative to dairy products to deliver probiotics. Bio-protection against several factors that affect their viability has been proposed in the food industry. In this study, probiotic Lactobacillus rhamnosus CECT 8361 was added to alginate-based coatings enriched with inulin and oligofructose and applied on fresh-blueberries. Probiotic viability, microbiological, physicochemical and sensory quality parameters of blueberries were monitored during 21 days of refrigerated storage. Also, L. rhamnosus CECT 8361 was tested for its antagonistic effect against inoculated Listeria innocua and E. coli O157:H7. Advantageously, prebiotic compounds allowed improving probiotic viability with counts above 6.2 log CFU/g for the entire period. Native microbiota counts remained under safe levels. Overall visual quality, odor and flavor were acceptable up to day 14 of storage. Regarding antimicrobial activity, L. rhamnosus CECT 8361 was able to reduce L. innocua counts by 1.7 log in inoculated blueberries. These results encourage further implementation of new fruit-based foods with multifunctional properties.